Because tax-exempt organizations generally operate for charitable or other beneficial purposes, most income that they receive is exempt from tax under the Internal Revenue Code. Tax-exempt organizations are permitted to engage in income-producing activities that are considered to be unrelated to their exempt purposes. However, income from these activities may be taxable. This study measures income, deductions, and tax imposed on tax-exempt corporate and trust entities' unrelated business income. Data are compiled from Form 990-T, Exempt Organization Business Income Tax Return.